INDIO, California (CNN) -- For some concertgoers, the Coachella Valley Music and Arts Festival really kicked into action on Day Two.
Festival attendees enjoy the music Saturday, Day Two of the Coachella music festival in Indio, California.
Day One was leisurely and pleasant -- the weather was mild, the acts were fairly mellow and the big headliner was Paul McCartney. On Day Two, someone took the dial and turned it up a notch, as the desert sun beat down a little harder, the music pumped a little louder and the crowds who packed the VIP tent threw a little more attitude.
There were the usual celebrity sightings. Jake Gyllenhaal and Reese Witherspoon snuck in the back just as rapper M.I.A. hit the stage, Paris Hilton took in Travis Barker and DJ AM's set in the Sahara tent and David Hasselhoff was spotted making out with a mystery lady near the restrooms.
Forty-six acts performed on five stages scattered about the grassy field of the Empire Polo Club near Palm Springs, California. Massive eco-friendly art installations fashioned from scrap metal and reclaimed wood doubled as shelter from the heat, as well as mini-stages for dancers and performance artists.
There was good buzz for thenewno2, an indie-pop band fronted by Oli Hecks and Dhani Harrison, whose vocals are reminiscent of his late father, George, but warmer, and less haunting.
"It's the first festival we've ever played, and our 12th gig overall," said Harrison. "Normally with festivals, people come to check you out, stand in the back, and then move on pretty quickly, even if they like you -- but people stayed! It's the best performance we've ever had."
Unfortunately Fleet Foxes was not so lucky. The Seattle,Washington, group's delicate baroque harmonies were drowned out by the world music beats of Thievery Corporation's percussion section bleeding over from the neighboring main stage, as one of their female vocalists crowd-surfed. As usual, the day's line-up was a mix of up-and-coming indie artists sprinkled with tried-and-true veteran acts.
The Killers have played Coachella in both capacities. The Las Vegas, Nevada, quartet received their first invitation from festival organizers in 2004, the same year their debut album, "Hot Fuss," was released. "We played at 11:30 a.m. in a tent. It was 150 degrees out, and backstage, it smelled like horse droppings," said drummer Ronnie Vannucci, referencing the fact that there are certain consequences to holding an event on a polo field in the desert.
This time, as the marquee act, The Killers enjoyed their own backstage compound decked out with a white picket fence, tablecloths and festive party lights in the shape of daisies. Palm trees gently swayed in the distance, silhouetted against the desert backdrop. You could hear the crowd going crazy for a feisty M.I.A. slotted on the main stage before The Killers.
Vannucci and his three bandmates had just rolled in on their tour bus from Vegas. He spoke with CNN while warming up his hands and wrists with drumming exercises. "With festivals, you have to realize the audience is not necessarily there to see YOU. So we'll play some stuff off our new album, 'Day and Age,' and work in some songs that everybody knows, like 'Mr. Brightside' from our first album."
Half an hour later, The Killers took the stage, opening their set with their latest hit, "Human." Frontman Brandon Flowers soon had the crowd singing the along to the perplexing lyrics, "Are we human, or are we dancer?"
At Coachella, it doesn't matter if you're human or if you're dancer. But if you're dancer, you'll probably be relegated to one of the mini-stages inside an art installation. "The first time I heard about Coachella 10 years ago, I thought, 'That could be the cool festival here in America," said Vannucci.
"It's since become a successful festival with good bands, swarms of people coming in from all over the world -- even art elements. It's strange to think we're headlining one night."